1. Field of the Invention
The present invention relates to a conductive polymer, a conductive layer, an electronic device, and electronic equipment, and more specifically to a conductive polymer having a high carrier transport ability, a conductive layer formed using the conductive polymer as a main material, an electronic device provided with the conductive layer and having a high reliability, and electronic equipment provided with the electronic device.
2. Description of Prior Art
Electroluminescent devices using organic materials (hereinafter, simply referred to as an “organic EL device”) have been extensively developed in expectation of their use as solid-state luminescent devices or emitting devices for use in inexpensive large full-color displays.
In general, such an organic EL device has a structure in which a light emitting layer is provided between a cathode and an anode. When an electric field is applied between the cathode and the anode, electrons are injected into the light emitting layer from the cathode side, and holes are injected into the light emitting layer from the anode side.
At this time, in a case where the molecular structure or molecular aggregation state of an organic EL material (hereinafter, also referred to as a “light emitting layer material”) is in a specific state, the injected electrons and the injected holes are not combined immediately, and a specific excited state is maintained for a certain time. As a result, the total energy of molecules becomes higher than that in a normal state, that is, a ground state by excitation energy. A pair of an electron and a hole in such a special excited state is called as an exciton.
When the exciton decays after the excited state thereof is maintained for a certain time, an electron and a hole are combined so that the increased energy, that is, the excitation energy is emitted as heat or light to the outside.
Such light emission occurs near the light emitting layer. The proportion of the excitation energy that is emitted as light to the total excitation energy is greatly influenced by the molecular structure or molecular aggregation state of the organic EL material.
Further, it has been found that a device structure, in which organic layers formed of organic materials having different carrier transport properties for electrons or holes from that for the light emitting layer is provided between the light emitting layer and the cathode and/or the anode, is effective in obtaining an organic EL device having a high light emitting efficiency.
Therefore, in order to obtain an organic EL device having a high light emitting efficiency, it is absolutely necessary to improve the molecular structure or molecular aggregation state of the light emitting layer material and a carrier transport layer material for transporting electrons or holes.
In addition, as described above, it is necessary to laminate a light emitting layer and organic layers having different carrier transport properties with each other (hereinafter, these layers are collectively referred to as “organic layers”) on the electrode. However, in the conventional manufacturing method using an application method, when such organic layers are laminated, mutual dissolution occurs between the adjacent organic layers, thereby causing a problem in that the characteristics of a resultant organic EL device, such as light emitting efficiency, color purity of luminescent color, and pattern accuracy are deteriorated.
Therefore, in the case where such organic layers are laminated, these organic layers have to be formed using organic materials having different solubilities in order to prevent the adjacent organic layers from being mutually dissolved.
In order to solve such a problem, a method for improving the durability of a lower organic layer, that is, the solvent resistance of the lower organic layer has been disclosed (see, for example, JP-A No. 09-255774). In this method, organic materials constituting the lower organic layer are polymerized to improve the solvent resistance of the lower organic layer.
Another method for improving the solvent resistance of a lower organic layer is found in JP-A No. 2000-208254. This publication discloses a method in which a curing resin is added to an organic material constituting the lower organic layer to cure the organic material together with the curing resin.
However, even in the case where such a method is employed in manufacturing an organic EL device, the characteristics of the resultant organic EL device are not so improved as to meet expectations in actuality.